The Forgotten Warrior
With a divided StarClan driving a treacherous rift between the four warrior Clans, the spirits of the Dark Forest are gaining strength. Ivypool's role as a spy becomes more dangerous with each passing day, and Dovewing is haunted by nightmares about the mountains.
Then an outsider appears in ThunderClan's midst, spreading discord and pushing the Clans farther apart. As tensions mount and Clanmates turn against one another, the warrior cats will be forced to choose whose word they can trust - before it's too late.
Erin Hunter is a collective pseudonym used by the several authors like Victoria Holmes, Kate Cary, Cherith Baldry, Inbali Iserles, Tui T. Sutherland, Kasey Widhalm and Rosie Best, in the writing of several juvenile fantasy novel series, which focus on animals and their adventures.
The name "Erin Hunter" was chosen for several reasons. First, if the authors used all of their own names, the books would be placed in different places in a library, making them hard to find. Second, they were trying to pick a surname that would place the books very close to the Redwall series by Brian Jacques, which was, at the time, the book series with the closest plot to Warriors.
Warriors: Omen of the Stars consists of six books. The current recommended reading order for the series is provided below.
Main series Warriors / Warrior Cats